This invention relates to the preparation of novel organophosphorus compounds. More particularly, this invention relates to the preparation of phosphonate adducts of propylene based lube-range olefins. The products obtained from the reaction of a propylene based lube olefin and various functionalized phosphites are unique in composition, structure and utility.
The use of metallic phosphorodithioate derivatives, such as zinc dithiophosphates, has been well-known for their multifunctional antioxidant/antiwear/anticorrosion properties in a variety of lubricant applications, especially in engine oils.
The use of ashless phosphorodithioate derivatives, such as alkylmercapto-alkyl-O,O-dialkyldithiophosphates (U.S. Pat. No. 2,759,010), phosphorodithioate esters (U.S. Pat. Nos. 3,544,465, 3,350,348 and 3,644,206), reaction products of sulfurized olefin adducts of phosphorodithioic acids (U.S. Pat. No. 4,212,753), and addition products of dihydrocarbyl thiophosphoric acids to conjugated dienes (U.S. Pat. No. 3,574,795), have found widespread use in a variety of lubricant applications as multifunctional anticorrosion, antiwear, and antioxidant additives, as well as in agriculture applications as herbicides and pesticides.
Lubricants, such as lubricating oils and greases, are subject to oxidative deterioration at elevated temperatures or upon prolonged exposure to the elements. Such deterioration is evidenced, in many instances, by an increase in acidity and in viscosity, and when the deterioration is severe enough, it can cause metal parts to corrode. Additionally, severe oxidation leads to a loss of lubrication properties, and in especially severe cases this may cause complete breakdown of the device being lubricated. Many additives have been tried, however, many of them are only marginally effective except at high concentrations. Improved performance is clearly needed.
Water (moisture) is another critical problem. In spite of even extraordinary precautionary efforts water is found as a film or in minute droplets in vessels containing various hydrocarbon distillates. This brings about ideal conditions for corrosion and damage of metal surfaces of the vessels and the materials contained therein. Also in the lubrication of internal combustion engines, for example, quantities of water are often present as a separate phase within the lubricating system. Another serious problem in respect to metallic surfaces in contact with adjacent metallic surfaces is the surface wear caused by the contact of such surfaces. One material capable of effectively coping with such problems as these simultaneously, is highly desirous.
The peroxide catalyzed reaction of dialkyl hydrogen phosphites with conventional olefins to give phosphonate derivatives is known as disclosed in U.S. Pat. No. 2,957,931. It has also been disclosed in U.S. Pat. Nos. 3,340,332 and 3,483,278 that O,O-dihydrocarbyl dithiophosphoric and monothiophosphoric acids add to olefinic compounds, i.e. monoolefins, multiolefins and conjugated diolefins in the presence of free radical initiators. In all of these patents, typical free radical initiators include ultraviolet light, gamma irradiation on chemical free-radical initiators such as peroxides, etc.
The reaction products in accordance with this invention are, however, novel lubricating fluids as well as novel additives. The incorporation of the herein disclosed phosphite derivatives onto the backbone of the propylene based lube olefin provides the basis for the unique internal synergistic extreme pressure/antiwear activity, thermal stability and lubricity. These phenomena are equally advantageous when these compositions are used at 100%, less than 100% or 10-90 wt. % partial fluid replacement levels or at 0-10 wt. % additive concentrations.
Accordingly, it is an object of this invention to provide lubricant compositions and fuel compositions having improved multifunctional capability comprising antioxidant/high temperature stabilizing properties, antiwear/EP activity with corrosion-inhibiting and friction-reducing characteristics. It is a further object to provide novel additive properties derived from the aforementioned phosphite derived adducts of propylene based olefins to such compositions.